U.S. Pat. No. 4,637,165 A, DE 31 08 212 A1 and DE 92 12 415 U1 each disclose casement/leaf arrangements in which the individual fitting parts are pushed at the end side into the open-ended C-shaped casement/leaf groove in the frame profile. A disadvantage with this type of installation is, in particular, that, when a fitting part needs to be exchanged, it is often difficult to carry out an exchange with the casement/leaf in the installed state.